JPH0150123B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor phase shifter with a wide band that continuously changes the phase of microwaves, for example.

[Conventional technology]

Conventionally, this type of semiconductor phase shifter is known to have a configuration consisting of a double-balanced modulator, as described, for example, in "IEICE technical research report MW80-102." , it can be used as an analog type semiconductor phase shifter by simply changing the method of applying the via voltage to the diode.

FIG. 3 is a perspective view showing a conventional semiconductor phase shifter. In the figure, 1 is a dielectric substrate, 2 is a strip conductor of a microstrip line, 3 is a ground conductor of a microstrip line, 4 is a branch line type 3dB hybrid coupler, and 5 is a first input/output terminal. , 6 is a matching termination terminal, 7 is a termination resistor connected to the matching termination terminal 6, and one end thereof is connected to the ground conductor 3. Reference numerals 8 and 9 denote a first coupling terminal and a second coupling terminal where the radio waves incident from the first input terminal 5 are equally distributed with a phase difference of 90 degrees and appear; 10 and 11;
are a first annular slot line and a second annular slot line each consisting of a gap provided in the ground conductor 3;
13 denotes each first and second annular slot line 1
The first and second branch slot lines 14, 15, 16, and 17 with short-circuited ends connected to the three branches provided at 0 and 11 are connected to the respective first and second annular slot lines 10, 1st surrounded by 11
is a diode in which one electrode is connected to a conductor surface 18 and a second conductor surface 19, and each diode 1
4, 15 and 16, 17 constitute a pair,
Each pair is connected with opposite polarity. each diode 1
The other electrodes 4, 15 and 16, 17 are connected to the respective first and second annular slot lines 10, 11, respectively.
and each of the first and second
It is connected to the ground conductor 3 with the branch slot lines 12 and 13 sandwiched therebetween. The bias applied to each diode 14, 15 is applied via the first conductor surface 18 and the ground conductor 3, and the bias applied to each diode 16, 17 is applied via the second conductor surface 19 and the ground conductor 3.
Although the voltage is applied through the power source, the illustration thereof is omitted in FIG. 3. 20 is a Wilson type 3dB power divider, 2
1 is a resistor, and 22 is a second input terminal. Note that the strip conductors 2 of the first and second coupling terminals 8 and 9 of the branch line type 3 dB hybrid coupler 4 are arranged perpendicularly to the first and second annular slot lines 10 and 11, respectively. Accordingly, the strip conductors 2 of each of the first and second distribution terminals 23 and 24, in which the radio waves incident on the 3 dB power divider 20 from the second input/output terminal 22 appear with the same phase and the same amplitude, are By arranging it orthogonally to the second branch slot lines 12 and 13, waves propagating through the microstrip line and waves propagating through the slot line can be smoothly exchanged.

The conventional double-balanced modulator is constructed as described above, and by applying a bias to each of the diodes 14 to 17 described below, it becomes an analog type semiconductor phase shifter with a phase change range of 360 degrees.

FIG. 4 is an explanatory diagram of the operation of only the balanced modulator in the semiconductor phase shifter of FIG. 3.
FIG. 4 shows a state viewed from the ground conductor 3 side shown in FIG. 3. As shown in the figure, if the bias voltage V applied to the bias terminal 26 of the bias circuit 25 made of conductor wire is a positive voltage +V ₀ , then
The diode 14 is applied with a forward bias and has a low impedance, and the diode 15 is applied with a reverse bias and has a high impedance, and the wave incident from the first branch slot line 12 propagates clockwise in the first annular slot line 10. Then, it is converted into a microstrip line and appears at the first coupling terminal 8. On the other hand, bias voltage V is set to negative voltage −V ₀
Then, each of the diodes 14 and 15 is in a bias state opposite to the above, and the first branch slot line 1
The wave incident from 2 is connected to the first annular slot line 10.
The signal propagates counterclockwise, is converted into a microstrip line, and appears at the first coupling terminal 8. In this way, the propagation direction of the radio waves propagating through the first annular slot line 10 differs depending on the polarity of the bias voltage applied to the bias terminal 26, and the two have opposite phases at the conversion section with the microstrip line.
Therefore, the radio waves appearing at the first coupling terminal 8 are
By changing the bias voltage from +V ₀ to -V ₀ , the phase is reversed by 180°.

5, 6, and 7 are explanatory diagrams of the operation of the semiconductor phase shifter of FIG. 3, respectively. Fifth
The figure shows a vector diagram outlining the relationship between the bias voltage and the amplitude and phase of the radio waves appearing at the first coupling terminal 8. As shown in the figure, the balanced modulator changes the bias voltage from +V ₀ to - By continuously changing V to ₀ , it is possible to control the amplitude to any desired amplitude while keeping the phase of the output radio wave at 0° and 180°.

FIG. 6 is a diagram for explaining the operation of an analog phase shifter with a phase change range of 360° using a double balanced modulator, and shows the first balanced modulator 27a.
bias terminal 28a, second balanced modulator 27b
The bias terminal of is designated as 28b. Here, the voltage applied to the bias terminal 28a of the first balanced modulator 27a is sin ω ₁ , where the time change in the amplitude of the output voltage of the balanced modulator shown in FIG. 4 is the angular velocity ω ₁ and the time t. Drive proportional to t. on the other hand,
The voltage applied to the bias terminal 28b of the second balanced modulator 27b changes the amplitude of the output voltage over time.
It is driven so as to be proportional to cos ω ₁ t having a phase difference of 90° with respect to the above output voltage. When the voltage applied to the diode is driven with such a time change, the radio waves incident on the 3 dB power divider 20 from the second input terminal 22 are split into equal parts, and then divided into the first and second terminals, respectively.
The signals propagate through the balanced modulators 27a and 27b, are combined in power by the 3 dB hybrid coupler 4 with a phase difference of 90 degrees, and appear at the first input/output terminal 5. As shown in FIG. 7, the radio waves appearing at the first input/output terminal 5 are radio waves that have passed through the first balanced modulator 27a (dotted line vector in FIG. 7) and the radio waves that have passed through the second balanced modulator 27b. It becomes a composite radio wave (solid line vector in Fig. 7) of the transmitted radio waves (dotted line vector in Fig. 7). That is, each of the first and second balanced modulators 27a, 27
The composite vector of the outputs of b becomes a vector whose amplitude is constant and whose phase changes continuously at an angular velocity of ω ₁ in response to changes in the amplitude of each output voltage, realizing a semiconductor phase shifter with a phase change range of 360°. It will be possible.

[Problem that the invention seeks to solve]

In the conventional semiconductor phase shifter as described above, the slot line is constructed using the ground conductor 3 of the microstrip line. Therefore, as the 3dB hybrid coupler 4, a branch line type 3dB hybrid coupler configured with a microstrip line or an interdigital type 3dB hybrid coupler is used, but the former has a usable band of 10
%, and since the latter is composed of a non-uniform medium, the propagation constants of even and odd modes of the coupled line are different, narrowing the usable band and making it impossible to obtain a band of one octave or more. is difficult.
By using a read-only memory (ROM) and a digital-to-analog converter (D/A converter) to drive the bias voltage, it is possible to obtain the required output voltage over a wide band. There was a problem in that the band of the 3 dB hybrid coupler 4 limited the usable band of the semiconductor phase shifter in this type of microwave.

The present invention was made to solve these problems, and aims to provide a semiconductor phase shifter with a wide band of one octave or more and a phase change range of 360°.

[Means for solving problems]

The semiconductor phase shifter according to the present invention includes a 3 dB hybrid coupler and a 3 dB power divider in the form of a wide surface coupled line using a triplate strip line made of a three-layer dielectric substrate, and a 3-dB power divider using a three-layer dielectric substrate. A balanced modulator is formed by a slot line consisting of a pair of slot lines provided on both sides of a ground conductor of a triplate type strip line consisting of a line.

[Effect]

In the semiconductor phase shifter of the present invention, the 3 dB hybrid coupler of the wide surface coupled line type composed of the triplate strip line has broadband performance, and the triplate type strip line and the triplate strip line are connected to each other. Since the conversion with the slot line consisting of a pair of slots provided on both sides of the ground conductor is also performed smoothly, broadband performance can be obtained.

〔Example〕

FIG. 1A is a perspective view showing a semiconductor phase shifter which is an embodiment of the present invention, FIG. 1B is a sectional view taken along line A-A of the semiconductor phase shifter of FIG. 1A, and FIG. Figure 1A
FIG. 2 is an exploded perspective view for explaining the structure of the semiconductor phase shifter of FIG. FIG. 2 shows a separated state of the three-layer dielectric substrate shown in FIG. 1A. In each of the above figures, 5 is the first input/output terminal, 6 is the matching termination terminal, 7 is the termination resistor, 21 is the resistor, and 22 is the second
29 is a dielectric upper layer board, 30 is a dielectric middle layer board, 31 is a dielectric lower layer board, 32 is a first ground conductor of the triplate type strip line, 3
3 is a second ground conductor of a triplate type strip line, and 34 is a wide surface coupled line type constructed by providing strip conductors 35 on both sides of a dielectric intermediate substrate 30.
A 3 dB hybrid coupler, 36, is a first balanced modulator constituted by a slot line 37 consisting of opposing slits provided in a first ground conductor 32 and a second ground conductor 33; This is a second balanced modulator composed of each first and second
The balanced modulators 36 and 38 each use two diodes 39 connected with opposite polarities to the surfaces of the first ground conductor 32 and the second ground conductor 33, respectively. The slot line 37 connects each bias terminal 4 via the surrounding conductor and the ground conductor.
Bias is applied from 0, 41, 42, and 43. Reference numeral 44 denotes a Wilkinson type 3 dB power divider composed of a triplate type strip line in which a strip conductor 35 and a resistor 21 are provided on one side of a dielectric intermediate substrate 30.

Next, the operation of the semiconductor phase shifter which is an embodiment of the present invention constructed as described above will be explained. After the radio waves incident from the second input/output terminal 22 are divided into equal power by the 3dB power divider 44,
It propagates through slot lines 37 provided on both sides of each first ground conductor 32 and second ground conductor 33, and sin ω ₁ t, After being modulated with an amplitude proportional to cos ω ₁ t, the propagation mode is converted to the triplate strip line again, and the phase difference is adjusted by the 3 dB hybrid coupler 34, which is a wide-band, wide-plane coupled line.
They are vectorially combined at 90 degrees, and an output appears at the first input/output terminal 5 with equal amplitude and whose phase changes continuously over 360 degrees. Each first and second balanced modulator 3
The amplitude of the output voltage of 6, 38 can be set to a value proportional to the required sin ω ₁ t, cos ω ₁ t by using a diode bias voltage driving method using read-only memory (ROM). . Therefore, in principle, a 3-dB hybrid coupler 34 of a wide-band, wide-plane coupled line type with no frequency characteristics for isolation is used, and a three-layer dielectric coupler 34 that integrates a triplate-type strip line and a slot line 37 is used. Since the semiconductor phase shifter is constructed using a solid substrate, there is little reflection due to discontinuous portions, and a broadband semiconductor phase shifter can be obtained.

In the above embodiment, the case where the semiconductor phase shifter of the present invention is used as a phase shifter with a phase change range of 360 degrees has been explained, but it is possible to use it as a four-phase phase modulator that drives a diode with a pulse voltage. Not even.

〔Effect of the invention〕

As explained above, the present invention constitutes a 3dB hybrid coupler and a 3dB power divider in the form of a wide surface coupled line using a triplate strip line using a three-layer dielectric substrate in a semiconductor phase shifter.
Since the balanced modulator is constructed with a slot line consisting of a pair of narrow gaps provided on both sides of the ground conductor of a triplate strip line, it is possible to create a semiconductor phase shifter with a much wider band than this type of conventional semiconductor phase shifter. This has the excellent effect of providing the following.

[Brief explanation of drawings]

FIG. 1A is a perspective view showing a semiconductor phase shifter which is an embodiment of the present invention, FIG. 1B is a sectional view taken along line A-A of the semiconductor phase shifter of FIG. 1A, and FIG. Figure 1A
FIG. 3 is an exploded perspective view for explaining the structure of a semiconductor phase shifter; FIG. 3 is a perspective view showing a conventional semiconductor phase shifter;
FIG. 4 is an operation explanatory diagram showing only the balanced modulator in the semiconductor phase shifter of FIG. 3; FIG.
6 and 7 are explanatory diagrams of the operation of the semiconductor phase shifter of FIG. 3, respectively. In the figure, 5...first input/output terminal, 6...
Matching termination terminal, 7... Termination resistor, 21... Resistor, 22... Second input/output terminal, 29... Dielectric upper layer substrate, 30... Dielectric middle layer substrate, 31... Dielectric lower layer substrate , 32...first ground conductor, 33...
Second ground conductor, 34...3dB wide surface coupled line type
Hybrid coupler, 35... strip conductor,
36...First balanced modulator, 37...Slot line, 38...Second balanced modulator, 39...Diode, 40-43...Bias terminal, 44...
It is a 3dB power divider. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1 Connect the first and second balanced modulators of the same configuration to the two terminals of the 3dB hybrid coupler that distribute equal power with a phase difference of 90°, and connect the outputs of these two balanced modulators to the 3dB power divider. has a configuration connected to
In an analog type phase shifter that is driven such that temporal changes in the amplitude of the outputs of the first and second balanced modulators are proportional to a sine function and a cosine function, respectively, the 3 dB hybrid coupler has three layers. The first and second balanced modulators are composed of a wide surface coupled line type 3 dB hybrid coupler using a triplate type strip line made of a dielectric substrate, and the first and second balanced modulators are
A slot line consisting of a pair of slits provided at opposite positions on both sides of the ground conductor of the triplate type strip line is arranged in a ring, and the ring-shaped slot line surrounds the opposing first and second conductor surfaces. One electrode of each of the two diodes is connected closely to each opposing position so that the diodes have opposite polarities, and the two diodes are connected to opposing positions of the first and second conductor surfaces. The other electrode of the four diodes connects the slot line to the conductor surface so as to bridge the gap between the pairs, and
A three-branch section is provided to connect a finite length slot line formed by a pair of gaps so that a transmission line extends from between the two diodes to the outside of the annular slot line. , the 3dB power divider connects the 3dB hybrid combiner and the first
and a triplate strip line made of the same dielectric substrate constituting the second balanced modulator, and the 3dB hybrid coupler, the first and second balanced modulators, and the 3dB power divider. The respective connections of the first and second balanced modulators both include a triplate strip line;
This triplate type strip line is constructed by converting it into a slot line consisting of a pair of gaps provided on both sides of the ground conductor, and the four slot lines surrounded by the annular slot line constituting the first and second balanced modulators are A semiconductor phase shifter comprising means for applying a bias to the diode through a conductor surface.